In this article, thermo-elastic and creep evolution behaviour of FERRITIC STEEL ROTATING DISKS with variable thickness are investigated. Four thickness profiles of uniform, convex, concave and linear are considered for the disk geometry. The material creep constitutive model is defined by the Θ projection concept, based on the experimental results existing in the literature. Loading applied is due to the inertial body force caused by the rotation and a constant temperature field throughout the disk. To achieve history of stresses and displacements, a numerical procedure using finite difference and Prandtl-Reuss relations is used. Stress and deformation histories are calculated using successive elastic solution method. In order to verify the solution approach, both composite and aluminum ROTATING DISKS were taken into account and the thermo-elastic and time-dependent creep behaviours for composite as well as the former for aluminum were obtained. Results from the current study were found to be in very good agreement with those available from literature in the area. It was shown that convex thickness profile DISKS display the least creep displacement, creep effective and circumferential stresses. Additionally, constant and concave thickness profiles were positively correlated with time while for linear and convex ones, it was found to have an inverse trend.

This article focused on the stress analysis of an edge crack in a thin hallow ROTATING functionally graded material (FGM) disk. The disk is assumed to be isotropic with exponentially varying elastic modulus in the radial direction. A comprehensive study is carried out for various combinations of the crack length and orientation with the different gradation of materials. The effect of non-uniform coefficient of thermal expansion on the distribution of stress intensity factor is also studied. The results which are normalized for the advantage of non-dimensional analysis show that the material gradation, the crack orientation and the crack length have significant influence on the amount of stress intensity factors.

Influence of creep on ratcheting behavior of ROTATING hollow DISKS under load and deformation controlled cyclic loading is investigated in this article. The disk material is assumed to obey nonlinear strain hardening curve and the Prager and Armstrong-Frederick kinematic hardening models are used to evaluate the back stress tensor in the stress space. A secondary creep equation is assumed to evaluate effect of creep time on cyclic loading behavior of the ROTATING hollow DISKS. The angular velocity is cycled within the two different stress limits of yield stress and twice the yield stress respectively. An interesting conclusion is that when creep is considered, both models predict the same ratcheting or shakedown behavior while; if creep is excluded, the models predict different ratcheting or shakedown behavior under mentioned loading conditions.

The comprehension of the anisotropy impacts on mechanical properties of the rolled STEEL sheets was investigated using a nonquadratic anisotropic yield function. In this study, experimental and modelling determination regarding the behaviour of an industrial rolled sheet for a FERRITIC stainless low-carbon STEEL were carried out. The parameters of the associated yield equation, derived from the three orthotropic yield functions proposed by Hill48, Yld96 and Yld2000-2d, were determined. Predictions and the evolution of normalized yield stress and normalized Lankford parameters (plastic strain ratio) obtained by the presented investigative are considered. The forecasts given by the YLD2000-2d criterion are consistent with that of the experience. In order to describe the path of strain behavior, the isotropic hardening function is described using the following four empirical standard formulae based on: Hollomon, Ludwick, Swift and Voce law. More accurately, the anisotropy coefficients of three yield functions are represented as a function of the longitudinal equivalent plastic strain.